NetworkPkg: Record user configured TargetIP/Port in iBFT

NetworkPkg: Record user configured TargetIP/Port in iBFT

Current ISCSI driver records redirected iSCSI targetIP/Port in iBFT
once redirection occurs, which removes the possibility of the OS
to reconnect to the configured IP for load balancing. The behavior
is not explicitly described in IBFT spec, though the MSFT expert
confirm we should record original user setting rather than
publish the redirected IP.

Thanks Sriram for reviewing and validating this patch in his test-bed.

Cc: Subramanian Sriram <sriram-s@hpe.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Zhang Lubo <lubo.zhang@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ye Ting <ting.ye@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Subramanian Sriram <sriram-s@hpe.com>